Magnetic resonance imaging (MRI) is an imaging technology that involves biomagnetism and nuclear spin. MRI has grown rapidly with the development of computer technology, electronic circuit technology, and superconductor technology. MRI uses a magnetic field and radio frequency (RF) pulses to cause nutation of precessing hydrogen nuclei (e.g., H+) in human tissue, thereby generating RF signals that are processed by a computer to form an image. When an object is placed in the magnetic field and irradiated with appropriate electromagnetic waves to make the object resonate, and upon analysis of the electromagnetic waves released thereby, the positions and types of the atomic nuclei that form the object may be identified. As a result, a precise three-dimensional image of the interior of the object may be drawn. For example, MRI may be used to scan a human brain to obtain a moving image of contiguous slices beginning at the top of the head and going all the way to the base of the head.
In conventional magnetic resonance systems, one system slot may support only one coil. Early magnetic resonance systems were configured with only a few slots. At present, the number of slots is insufficient for advanced later-developed applications such as full-body matrix imaging.
Heretofore, the method used to make a system compatible with multiple coils has been to increase the number of slots in the system. However, increasing the number of system slots may result in changes to the patient table, system cables, and receiver. These changes may significantly increase the cost of the system. Moreover, when the number of system slots in the original system is insufficient, upgrading the system to include multiple slots is difficult. Another approach has been to utilize control bus technology to send an upper-level command to a decoder that then controls switching of the appropriate RF channel according to the content of the command. When the control bus method is used, software is used for alterations and a corresponding control line in the cable is used. In addition, a clock signal is introduced that may cause interference to the system.